Service level objectives support on @Timed annotation

micrometer-core/src/main/java/io/micrometer/core/annotation/Timed.java

@@ -74,6 +74,15 @@
      */
     boolean histogram() default false;
 
+    /**
+     * List of service level objectives to calculate client-side for the
+     * {@link io.micrometer.core.instrument.Timer} in seconds. For example, for a 100ms
+     * should be passed as {@code 0.1}.
+     * @return service level objectives to calculate
+     * @see io.micrometer.core.instrument.Timer.Builder#serviceLevelObjectives(java.time.Duration...)
+     */
+    double[] serviceLevelObjectives() default {};
+
     /**
      * Description of the {@link io.micrometer.core.instrument.Timer}.
      * @return meter description

micrometer-core/src/main/java/io/micrometer/core/aop/TimedAspect.java

@@ -20,14 +20,18 @@
 import io.micrometer.core.annotation.Incubating;
 import io.micrometer.core.annotation.Timed;
 import io.micrometer.core.instrument.*;
+import io.micrometer.core.instrument.util.TimeUtils;
 import org.aspectj.lang.ProceedingJoinPoint;
 import org.aspectj.lang.annotation.Around;
 import org.aspectj.lang.annotation.Aspect;
 import org.aspectj.lang.reflect.MethodSignature;
 
 import java.lang.reflect.Method;
+import java.time.Duration;
+import java.util.Arrays;
 import java.util.Optional;
 import java.util.concurrent.CompletionStage;
+import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
 import java.util.function.Predicate;
 
@@ -254,7 +258,11 @@ private Timer.Builder recordBuilder(ProceedingJoinPoint pjp, Timed timed, String
             .tags(EXCEPTION_TAG, exceptionClass)
             .tags(tagsBasedOnJoinPoint.apply(pjp))
             .publishPercentileHistogram(timed.histogram())
-            .publishPercentiles(timed.percentiles().length == 0 ? null : timed.percentiles());
+            .serviceLevelObjectives(
+                    timed.serviceLevelObjectives().length > 0 ? Arrays.stream(timed.serviceLevelObjectives())
+                        .mapToObj(s -> Duration.ofNanos((long) TimeUtils.secondsToUnit(s, TimeUnit.NANOSECONDS)))
+                        .toArray(Duration[]::new) : null);
+
         if (meterTagAnnotationHandler != null) {
             meterTagAnnotationHandler.addAnnotatedParameters(builder, pjp);
         }

micrometer-core/src/main/java/io/micrometer/core/instrument/Timer.java

@@ -22,6 +22,7 @@
 import io.micrometer.core.instrument.distribution.HistogramSupport;
 import io.micrometer.core.instrument.distribution.ValueAtPercentile;
 import io.micrometer.core.instrument.distribution.pause.PauseDetector;
+import io.micrometer.core.instrument.util.TimeUtils;
 
 import java.time.Duration;
 import java.util.Arrays;
@@ -100,7 +101,11 @@ static Builder builder(Timed timed, String defaultName) {
         return new Builder(timed.value().isEmpty() ? defaultName : timed.value()).tags(timed.extraTags())
             .description(timed.description().isEmpty() ? null : timed.description())
             .publishPercentileHistogram(timed.histogram())
-            .publishPercentiles(timed.percentiles().length > 0 ? timed.percentiles() : null);
+            .publishPercentiles(timed.percentiles().length > 0 ? timed.percentiles() : null)
+            .serviceLevelObjectives(
+                    timed.serviceLevelObjectives().length > 0 ? Arrays.stream(timed.serviceLevelObjectives())
+                        .mapToObj(s -> Duration.ofNanos((long) TimeUtils.secondsToUnit(s, TimeUnit.NANOSECONDS)))
+                        .toArray(Duration[]::new) : null);
     }
 
     /**

micrometer-core/src/test/java/io/micrometer/core/aop/TimedAspectTest.java

@@ -23,6 +23,7 @@
 import io.micrometer.core.instrument.Meter.Id;
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.Timer;
+import io.micrometer.core.instrument.distribution.CountAtBucket;
 import io.micrometer.core.instrument.distribution.DistributionStatisticConfig;
 import io.micrometer.core.instrument.distribution.pause.PauseDetector;
 import io.micrometer.core.instrument.search.MeterNotFoundException;
@@ -34,6 +35,7 @@
 import org.springframework.aop.aspectj.annotation.AspectJProxyFactory;
 
 import javax.annotation.Nonnull;
+import java.util.Arrays;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
 import java.util.function.Predicate;
@@ -95,6 +97,29 @@ void timeMethodWithLongTaskTimer() {
             .size()).isEqualTo(1);
     }
 
+    @Test
+    void timeMethodWithSloTimer() {
+        MeterRegistry registry = new SimpleMeterRegistry();
+
+        AspectJProxyFactory pf = new AspectJProxyFactory(new TimedService());
+        pf.addAspect(new TimedAspect(registry));
+
+        TimedService service = pf.getProxy();
+
+        service.sloCall();
+
+        assertThat(Arrays
+            .stream(registry.get("sloCall")
+                .tag("class", getClass().getName() + "$TimedService")
+                .tag("method", "sloCall")
+                .tag("extra", "tag")
+                .timer()
+                .takeSnapshot()
+                .histogramCounts())
+            .mapToDouble(CountAtBucket::bucket)
+            .toArray()).isEqualTo(new double[] { Math.pow(10, 9) * 0.1, Math.pow(10, 9) * 0.5 });
+    }
+
     @Test
     void timeMethodFailure() {
         MeterRegistry failingRegistry = new FailingMeterRegistry();
@@ -621,6 +646,11 @@ void call() {
         void longCall() {
         }
 
+        @Timed(value = "sloCall", extraTags = { "extra", "tag" }, histogram = true,
+                serviceLevelObjectives = { 0.1, 0.5 })
+        void sloCall() {
+        }
+
     }
 
     static class AsyncTimedService {

micrometer-core/src/test/java/io/micrometer/core/instrument/binder/jersey/server/MetricsRequestEventListenerTimedTest.java

@@ -21,6 +21,7 @@
 import io.micrometer.core.instrument.Tags;
 import io.micrometer.core.instrument.binder.jersey.server.resources.TimedOnClassResource;
 import io.micrometer.core.instrument.binder.jersey.server.resources.TimedResource;
+import io.micrometer.core.instrument.distribution.CountAtBucket;
 import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
 import org.glassfish.jersey.server.ResourceConfig;
 import org.glassfish.jersey.test.JerseyTest;
@@ -93,6 +94,20 @@ void resourcesWithAnnotationAreTimed() {
         assertThat(registry.get("multi2").tags(tagsFrom("/multi-timed", 200)).timer().count()).isEqualTo(1);
     }
 
+    @Test
+    void sloTaskTimerSupported() throws InterruptedException, ExecutionException, TimeoutException {
+        target("timed-slo").request().get();
+
+        CountAtBucket[] slos = registry.get("timedSlo")
+            .tags(tagsFrom("/timed-slo", 200))
+            .timer()
+            .takeSnapshot()
+            .histogramCounts();
+        assertThat(slos.length).isEqualTo(2);
+        assertThat(slos[0].bucket()).isEqualTo(Math.pow(10, 9) * 0.1);
+        assertThat(slos[1].bucket()).isEqualTo(Math.pow(10, 9) * 0.5);
+    }
+
     @Test
     void longTaskTimerSupported() throws InterruptedException, ExecutionException, TimeoutException {
         final Future<Response> future = target("long-timed").request().async().get();

micrometer-core/src/test/java/io/micrometer/core/instrument/binder/jersey/server/resources/TimedResource.java

@@ -54,6 +54,13 @@ public String timed() {
         return "timed";
     }
 
+    @GET
+    @Path("timed-slo")
+    @Timed(value = "timedSlo", histogram = true, serviceLevelObjectives = { 0.1, 0.5 })
+    public String timedSlo() {
+        return "timed";
+    }
+
     @GET
     @Path("multi-timed")
     @Timed("multi1")